Axle Collection Thread

[Lego2016Lego]

And another 9 stud wide version here, driven by worm gear.

After having an idea with small bevel gears, I looked for benchmarks, and found that I wasn't alone. EFFEUNO471 made a similar concept a while ago - see here.

I created my version too, to be honest, I have no clue how to motorize it in a compact way, but was an interesting experiment.

Mini 4x4 crawler chassis, for LDD file CLICK.

Does it have steering?

And do you have some pics of the real model?

[agrof]

Yes it has, but bit weird placed, the steering axle is below of the drive axle.

Sorry, no real model, I just played around in LDD.

[Lego2016Lego]

Ok, thanks!

[syclone]

Hi there!

Have been working on another project, no name right now, I hope it is better than my first design

(steering rack on the rear)

BRICKSAFE

[Didumos69]

Hi there!

Have been working on another project, no name right now, I hope it is better than my first design

(steering rack on the rear)

BRICKSAFE

This looks much better!

Although some might say that the shockabsorber placed on one side of the wishbones causes too much friction in the whole setup, I think the combination with the vertical lift arms makes this a good setup. The only thing I would be worried about are the slightly angled steering links. This is not sloppy or so, but it could cause some toe-out. If you could manage to move the tooth rack half a stud closer to the wheel axles (or move the wishbones - or A-arms if you like - half a stud closer to the tooth rack), then that would align the whole setup perfectly. In addition, you could consider widening the A-arms upto 3 studs by placing 2L or 3L thin lift arms to the sides of the A-arms. That would reduce play in the A-arms even further. But I wouldn't move the shockabsorber further away from the wheel axles.

If in the end the single shockabsorber would turn out too weak to carry your vehicle, you could also use the axle holding the lower A-arm as a longitudinal torsion bar.

Good progress!

Edited April 22, 2016 by Didumos69

[syclone]

This...gress!

Thanks for the the advice, I will try to integrate the things you said onto my next prototype!

[Kiwi_Builder]

Two independent suspended and driven steering axles. Both axles have a different steering angle

lxf

I'm interested in checking out the LDD file for it, but your link doesn't appear to be working. Instead of giving the download it just takes you to the DoktorBrick.de website Could you please fix it up so that we can download the file? Cheers

[Imanol BB]

Hi again, look at the axle that Madoca designed for his modded version of the Rm8´s Toyota http://www.eurobricks.com/forum/index.php?showtopic=130679entry2540842 , i think it is really amazing and clever.

I also was trying to make it in LDD, i will post the file later.

[syclone]

I think i'm done with the front axle, had some problems because I was so stupid to put 5l thin beams between the suspension arms with positive caster angle

Most of the axle is the same as before, but I added torsion bar and two more shocks.

LDD

BRICKSAFE

Btw,now you know the name of my project

Edited April 26, 2016 by LXF

[agrof]

Cool, simple solution for positive caster angle, while keeping the main structure perpendicular. :thumbup:

As far I know, it is not the first time, that somebody creates such solution, but it doesn't degradate Your version!

[Didumos69]

I think i'm done with the front axle, had some problems because I was so stupid to put 5l thin beams between the suspension arms with positive caster angle

Most of the axle is the same as before, but I added torsion bar and two more shocks.

Very nice to see how you used a longitudinal torsion bar ! Good choice also to apply shockabsorber and torsion to the upper wishbone, especially now that you're missing the vertical liftarms. You could even consider moving the yellow shockabsorber to the upper wishbone too. That would also put the shockabsorbers-wishbone mounts in double shear.

As to the torsion bar, my impression is that it actually works against the shockabsorbers up to the point where the wishbones come horizontal. You could tweak the torsion tension as shown in this image.

Good luck with this project!

Edited April 26, 2016 by Didumos69

[syclone]

Very nice to see how you used a longitudinal torsion bar ! Good choice also to apply shockabsorber and torsion to the upper wishbone, especially now that you're missing the vertical liftarms. You could even consider moving the yellow shockabsorber to the upper wishbone too. That would also put the shockabsorbers-wishbone mounts in double shear.

As to the torsion bar, my impression is that it actually works against the shockabsorbers up to the point where the wishbones come horizontal. You could tweak the torsion tension as shown in this image.

Good luck with this project!

Cool, simple solution for positive caster angle, while keeping the main structure perpendicular. :thumbup:

As far I know, it is not the first time, that somebody creates such solution, but it doesn't degradate Your version!

Thanks!

@Didumos69- the actual setup I am using is optimized for the project, with the torsion bars I lovered it half stud ,but thanks for the idea.

Btw , is the wheel size good for that wide setup?

And a final question, is positive caster angle necessary on rear non-steered wheels?

Edited April 26, 2016 by LXF

[Didumos69]

Btw , is the wheel size good for that wide setup?

And a final question, is positive caster angle necessary on rear non-steered wheels?

Wheel size and width don't appear as a strange combination to me, but I don.t know exactly what you're going to build so I can not really say.

Non-steered rear axles don't need caster angle. Positive caster - as in your build - means that the steering axis is tilted slightly backwards. This causes the tyre to touch the ground behind the point where the imaginary line through the tilted steering axis touches the ground. The effect is that the wheel wants to trail the steering axis, just like a wheel of a shopping trolley wants to trail its steering axis. This gives a car straight-line stability. Rear axles don't have a steering axis, so they don't need this kind of effect. Camber angle would be nice though. Negative camber is especially useful when it is only introduced when the suspension is compressed (some refer to this as progressive camber). It will keep the tyres flat on the ground in turns. Read this article if you want to know everything about camber, caster, toe-in/out, tyre scrub etc: http://www.motoiq.co...-and-Scrub.aspx

EDIT: To be slightly more complete: When drive is applied to the front axles - as in your case - then caster angle is not enough to obtain straight-line stability. Again, think of the caster effect as a wheel trailing the steering axis like the wheel of a shopping trolley. Now imagine drive is applied to the wheel and it's easy to understand that the trailing effect will be disturbed. For FWD and AWD you often see a balanced combination of positive caster angle and kingpin inclination. The latter adds to straight-line stability, because it causes the car to lift as the wheels are turned (as long as the point where the steering axis-line touches the ground does not surpass the mid-point of the tyre).

Edited April 27, 2016 by Didumos69

[ChocolateEinstein]

mmk, I've got some to share

Trailing axle

Download

curbjumper front axle

​solid axle

Download

curbjumper rear axle

solid axle

Download

weird steered axle

independent

Download

rear trophy truck faker axle

independent trailing arms

Download

[syclone]

Applied kingpin inclination and redesigned the structure, still not happy with the result, I think the entire project (the car itself) will take around 1-1'5 years to complete

And only after this I will make the Skyline

Edited April 30, 2016 by LXF

[skppo]

Applied kingpin inclination and redesigned the structure, still not happy with the result, I think the entire project (the car itself) will take around 1-1'5 years to complete

And only after this I will make the Skyline

*snip*

I don't think the lower balljoint (or the pin) is going to stay connected for very long with the hard spring mounted on the lower wishbone.

[JJ2]

@LXF

your UJ needs to be in the steering pivot for proper geometry.

[Lipko]

@LXF

your UJ needs to be in the steering pivot for proper geometry.

He uses a CV joint too, so it should be okay geometrically, though the U-joint will have an unhealthy angle when steered to maximum (more extreme angle than it would have with the UJ being in the steering pivot).

Also that part holding the wheel axle is not fixed so pretty much the U-joint rubbing to the hub will keep the vertical angle of the wheel. For these kind of problems (complicated and often fragile hub, shock absorber on the bottom arm which cannot be connected to the top arm, etc) I don't see why this advanced suspension geometry is needed at this scale. The slack of parts will have bigger effect that those nifty angles.

Edited April 30, 2016 by Lipko

[Didumos69]

He uses a CV joint too, so it should be okay geometrically, though the U-joint will have an unhealthy angle when steered to maximum (more extreme angle than it would have with the UJ being in the steering pivot).

Also that part holding the wheel axle is not fixed so pretty much the U-joint rubbing to the hub will keep the vertical angle of the wheel. For these kind of problems (complicated and often fragile hub, shock absorber on the bottom arm which cannot be connected to the top arm, etc) I don't see why this advanced suspension geometry is needed at this scale. The slack of parts will have bigger effect that those nifty angles.

All true. Still, I appreciate LXF's search for a properly angled front suspension. @LXF, I hope you don't give up yet!

A few practical things that this setup can improve on:

- Use the 5.5 axle with end-stop for your wheel hub. That one cannot drop out of the U-joint.

- To better hold the wheel axle you could do something like this:

(I must have an idea somewhere for a hub that could fit even better, I'll post here when I find it.)

Edited April 30, 2016 by Didumos69

[Didumos69]

@LXF, I found the hub I was talking about in the previous post. It was the result of my first exploration with an angled hub. In fact the tilted setup still is the base of the wheel hubs that I use in my 'Steppenwolf'-platform. It is a tight setup, but the tightness also makes it sturdy.

Advantages:

- Alows for a setup that combines FWD with kingpin inclination and caster angle.

- Allows the lower wishbone to be placed upside-down, which is better if you want to attach a shockabsorber to it.

- Lets you insert the U-joint into the hub all the way, while giving the U-joint enough space to bend in all directions.

Disadvantages:

- The pivot ball joint is placed on a half stud offset, which requires a (tooth) rack that is an even number of studs long.

The setup also brings the wheel axle 0.5+ stud down compared to a normal setup. Whether this is a pro or a con depends on what you're building.

LXF-file here.

EDIT: @LXF, perhaps you should make a [WIP] topic about your project for this kind of discussion.

Edited April 30, 2016 by Didumos69

[syclone]

@LXF, I found the hub I was talking about in the previous post. It was the result of my first exploration with an angled hub. In fact the tilted setup still is the base of the wheel hubs that I use in my 'Steppenwolf'-platform. It is a tight setup, but the tightness also makes it sturdy.

Advantages:

- Alows for a setup that combines FWD with kingpin inclination and caster angle.

- Allows the lower wishbone to be placed upside-down, which is better if you want to attach a shockabsorber to it.

- Lets you insert the U-joint into the hub all the way, while giving the U-joint enough space to bend in all directions.

Disadvantages:

- The pivot ball joint is placed on a half stud offset, which requires a (tooth) rack that is an even number of studs long.

The setup also brings the wheel axle 0.5+ stud down compared to a normal setup. Whether this is a pro or a con depends on what you're building.

LXF-file here.

EDIT: @LXF, perhaps you should make a [WIP] topic about your project for this kind of discussion.

All true. Still, I appreciate LXF's search for a properly angled front suspension. @LXF, I hope you don't give up yet!

A few practical things that this setup can improve on:

- Use the 5.5 axle with end-stop for your wheel hub. That one cannot drop out of the U-joint.

- To better hold the wheel axle you could do something like this:

(I must have an idea somewhere for a hub that could fit even better, I'll post here when I find it.)

He uses a CV joint too, so it should be okay geometrically, though the U-joint will have an unhealthy angle when steered to maximum (more extreme angle than it would have with the UJ being in the steering pivot).

Also that part holding the wheel axle is not fixed so pretty much the U-joint rubbing to the hub will keep the vertical angle of the wheel. For these kind of problems (complicated and often fragile hub, shock absorber on the bottom arm which cannot be connected to the top arm, etc) I don't see why this advanced suspension geometry is needed at this scale. The slack of parts will have bigger effect that those nifty angles.

@LXF

your UJ needs to be in the steering pivot for proper geometry.

I don't think the lower balljoint (or the pin) is going to stay connected for very long with the hard spring mounted on the lower wishbone.

Thanks for your opinions, this help is really appreciated!

Will start a new topic about the project

The suspension from Steppenwolf project doesn't fits inside the car

[PunkTacoNYC]

Here are the axles from my Chili Crawler

Front axle:

It features a geared down L motor for steering and an XL motor for propulsion (geared down 1:5.001). I mounted the motor parallel to the axle so that there would not only be more ground clearance, but there is absolutely no gear slippage. In fact, there is more slippage in the steering than the drive! (But still very little ). LXF

Rear Axle:

It features unimog portal hubs WITH mounting axles for extra rigidity. Note: because there are 3 pins on the portal hubs and 4 possible mounting positions - rotations - for the axles, you must line the axles and pins up the with wheels, exactly). It is driven by a XL motor and is geared down 1:5.001. LXF

Enjoy

[syclone]

With the newer version of LDD there is L motor.Also you can use ctrl+K to make pics in LDD.

Nice axles!

[Imanol BB]

Hi, here is another model i have made for an small unimog, it is in WIP state right now, i will give more information tomorrow:

http://bricksafe.com/files/imanol/mini-portal-hub-axle/front%20drivetrain.lxf

Edited May 24, 2016 by ImanolBB

[2LegoOrNot2Lego...]

Cool! So far so good... Really curious what wheels you will use!